Ignition distributor



March 7, 1944. H. l.. HARTZELL.

IGNITION DISTRIBUTOR Filed sept. '7, 1942 A v 52. Nb

E w, 7.5% l

' Patented Mar. 7,

2,343,455 IGNITION ms'ramu'roa Herman L. Hartlell, Anderson, Ind.,

General Motors Corporation, Detroit, Mich., a

corporation of Delaware signor t Appunti@ september 1, 1942, serai No.451.605

j schim. (ciano-is) Th" s invention relates to an ignition distributorfor aviation use and its aim is to provide a sealed distributor forcontaining air or other gaseous medium under pressure 'whereby thedistributor will give satisfactory operation at high altitude.

Further objects and advantages of the presentv invention will beapparent from the following' Fig. 1 is a plan view of a distributorconstructed in accordance with the present invention.

Fig. 2 is a sectional view on the line 2 2 .of Fig. 1. 1

Referring to the drawing, 20 designates a frame ofthe engine providingan opening at 2| which receives a gear 22 driven by the engine andconnected to a shaft 23 by a nut 24 engag ing the screw threaded end ofthe shaft and locked lby a washer 25 having tangs bent along the flatsides of the nut 24. 'I'he shaft 23 1S supported by ballbearings 21 and38 having respectively outer races 28 and 3| and inner races 28 and 32.The housing 40 which supports these bearings .is an aluminum` castingproviding an annular shoulder 4| .against which the outer race 3l ofbearings. is secured by 'an annular threaded bushing 42. Spacing washer43 is located between 'gear 22 and the inner race 32 which bears againsta collar 44 secured to shaft 23 a pin 45.

is received by a hard metai'insert 46 inthe central tubular portion 41of` the housing y40'. A

tubular bushing 48 threadedly connected with the upper end of the part41 confines a sleeve 49 against thebearing outer race28 and insert 46.vSleeve 49 provides a recess for receiving a rubber seal 58 whichreceives a bushing 5| which clears the shaft 23' and which provides aground surface 52 receiving the ground surface provided by an anrillarboss' 53 of a seal ring `54 providing alpocket for receiving a softrubber washer 55 against which pressureis exerted by four dished springwashers 56y confined between washer 55 and a shoulder 51 of/shaft 23.The resilient discsv 51 urge -the seal boss 53 against the seal ring andthus substantially retard escape of air or gas under pressure within thehousing 48 downwardly along the shaft 23.

Some of this pressure fluid may escape and will pass downwardly throughvthe bearing 21 into a chamber .80 fromwhich'escape is substantiallyprevented by another set of sealing parts Sla 'I'he outer race 28 ofbearing 21 through 66a" which are a counterpart of those numbered 5|through 68.

Housing is attached by screws 4| to a lightweight metal plate 82 havingsteel inserts 63 engaging the threads of the screws Il. Plate 82 isattached by screws 84 to frame 20 and is located relative thereto by adowel pin 65. Plate 62 provides a support for the side wall portion 86of a metal shield secured thereto by screws 61 and 88. The shield sidewall portion 86 extends from the plate 62 above the top of thedistributor and receives a shield cover secured by the screws 61 to theside wall portion 66.

- The housing 48 carries a rubber sealing ring 1li which receives anonconducting distributor cap or head 1I which is reinforced by a metalspider 12 which together with the head 1| is secured to the housing 44by a ring 'I3 having internal flange 14 engaging an external flange 15of the spider 12 and having screw threads 16 ,engaging screw threadsofthe housing 40. The 4nut 13 can be turned by a spanner wrench engagingholes 11 in the nut.

Distributor head 1| has a skirt 8| extending below a surface 82. Abovethe surface 82, the head 1| provides a circular row of hexagonal pockets82a each of which receives a rubber sealing washer 83 and the hex flange84 of a distributor post or terminal 85,-the shank of which extends intoa cable receiving recess 81. The bottom surface 88 of the recess 81receives a plane washer 89 and a cupped spring washer 90. When the upperend of shank 88 is riveted over at 8| against the washer 80 the rubberringl 83 is compressed 'and squeezed against the recess 82a andagainstthe shank 86 so as to prevent the escape of pressure fluid in thehousing 46 around the shank 86 of the terminal 85.

In order to seal each cable end and vthus to prevent an arc from thecable end to the grounded. cage 12, each socket 61 receives a rubberseal bushing 92 which can be forced around the in- Sulaton 93 of a wire84 by screwing down a nonf conducting nut 95 having Spanner .wrenchrecesses or holes 86. The screwing down of nut 95 forces a nonconductingbushing 31 against the effectively sealed and the wire 84 of the cableis held in position with its strands engaging av metal pin 98 extendingfrom the post 85.

The number of sockets 81 equals the numberl of spark plugs of theengines' The sparking impulses are furnished by an ignition coil (notshown) whose secondary terminal is connected with a wire havinginsulation I0| and received by a socket |02 which, like socket 01.contains a seal bushing 02 urged downwardly by a nut 0l which forces abushing 01 against the upper end o! a seal bushing 02. The strands ofwire |00 are engaged by a pin |02 extending from the shank |04 of aterminal |05 which, like the terminal 00, has a hex ilange 0I bearingagainst a seal ring 0I which is compressed when the upper end ofterminal |05 is riveted as at |00 down against a spring washer 90 whichbears against a plane washer 00. The terminal |05 projects into a grooveof a metal ring I 0 which is soldered to a distributor segment |I whichtogether with the segment are imbedded in a nonconducting distributorrotor block ||2 having a metal insert III providing a hub which issplined at Ill to the upper end of shaft 23 and which is clamped againstthe shoulder 51 of shaft 23 by screwing down a nut Ill engaging theupper threaded end of the shaft 20 and held in position by Washer IIIhaving tangs |I1 which can be bent against the ilats of nut H5.

Head 1| provides a pocket for receiving a soft rubber self-closing valve|20 having a flange |2| provided with a bead |22 received by a groove inthe upper surface of the internal flange |23 which closely fits aroundthe valve |20. A nonconducting washer |24 rests upon the iiange |2| andis engaged by a nonconducting nut |25 having spanner wrench holes |20for turning it. The screwing down of the nut |25 forces the washer |20down against the flange |2| and against the flange |20 thus sealing thevalve |20 to the distributor head 1|. The valve |20 provides aneedle-passage |30 for receiving a needle nozzle oi' a compression pumpby which air and other gas can be forced under pressure into the chamberprovided by the housing 40 and the head 1|. When the nomle is removedthe lips |3| close together and prevent escape of pressure fluid outthrough the valve.

Since the head 1| is subjected to internal pressure which isconsiderably above atmospheric pr at h'igh altitude and since the head1| may be subjected to heat of the engine, there is a tendency of thehead to become distorted. Such distortion would be apt to open one ormore of the seals; but such distortion is substantially prevented by themetal reinforcing spider 12.

From the foregoing description it is apparent that the distributorhousing is gas-tight for all practical purposes. It will retain gasunder pressure for a substantial period and thus prevent the groundingof ignition currents, although the voltage required for producing aspark at a spark plug is high enough to cause an arc of several inchesin the surrounding atmosphere at high altitudes.

While the embodiment of the present invention as herein disclosed,constitutes a preferred form. it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

l. A gas-tight ignition distributor for use at high as well as lowaltitude comprising a housing, a nonconducting distributor coverattached to the housing and providing therewith a chamber for receivinggas under pressure, means ior admitting 8&8 under pressure to thechamber. means for sealing the Joint between the cover and housing, ashaft rotatably supported by the housing and extending into the chamber,a rotor within the chamber driven by the shaft, a shaft seal forpreventing the escape of gas from the chamber along the shaft, aconducting segment carried by the rotor, distributor posts carried bythe cover-and extending therethrough and receiving sparking impulsesdistributed by the rotor segment, a terminal carried by the cover andextending therethrough for making an electrical connection with a sourceof sparking impulses and with the rotor segment` cable receiving socketsprovided by the cover and respectively enclosing the posts and terminal,insulated cables received by the sockets having their conductingportions respectively in engagement with the posts and terminal, sealingmeans respectively between the posts and terminal and the cover, andsealing means respectively between the walls of the cable receivingsockets and the insulation of the cables.

2. An ignition distributor according to claim l in which distributorposts and terminal are each of rivet-like formation, the head of whichis located within the chamber, there being a sealing gasket surroundingthe shank of the rivet and between the rivet head and an inner wall ofthe cover, the rivet shank extending beyond an outer wall of the coverand through a cupped resilient metal washer and deformed against saidwasher.

3. An ignition distributor according to claim 1 in which the insulationof the cable received by a socket is surrounded by a soft rubber sleeveand which means screw-threadedly attached to the cover engage the sleeveto maintain it under longitudinal compression to force it against theinterior wall of the socket and to constrict it around the cableinsulation in order to provide a seal and to resist longitudinalmovement of the cable within the socket whereby the 'conducting portionof the cable is maintained in engagement with the post or terminalwithin the socket.

4. An ignition distributor according to claim 1 having also a metalspider for resisting distortion of the cover due to pressure in thechamber, and means securing the spider upon the cover and the cover uponthe housing.

5. A gas-tight ignition distributor for use at high as well as lowaltitudes and comprising detachable members providing a chamber forreceiving .gas under pressure, a shaft extending through one of themembers, conductors extending through the other members, a distributorrotor driven by the shaft and having a segment for distributing sparkingimpulses from a conductor to other conductors in recurrent sequence.means for admitting gas under pressure to the chamber, and devices forpreventingescape of gas from the chamber around the shaft, around theconductors and at the joint between the chamber members.

HERMAN L. HAR'IZELL

